M39 / NGC 7092, open cluster: The Night of Two Clusters, part 1

Hungry-hungry-hungry for the stars after two months long break :)

 

Acquisition time (start of a session): JD2456858.35046296 (20.07.2014, 00:25:40 MSK)

Equipment:

Canon EOS 60D (unmodded) running Magic Lantern firmware override fitted with Baader Planetarium MPCC MkIII coma corrector on Celestron OMNI XLT 150 mm Newtonian riding on Skywatcher NEQ-6 Pro mount with counterweight shaft extention.

Aperture 150 mm

Focal length 750 mm

Tv = 45 seconds (I'm progressing, but it's better to get a guider :)

Av = f/5

ISO 3200

Exposures: 30 of 50 (plus 31 dark frames plus 27 flats and respective master offset library).

Processing: Images were converted into .DNG and fed to DSS. Final touches were "creatively" done in Photoshop. I have tried to protocol the processing in order to adhere to it next time, so in gereral it looks like:

1) setting gamma to 2,75;

2) setting black level rougly 8-10 8-bit units below actual minimum;

3) applying higly assimmetric sigma-like curve (that's "creative" :);

4) fine-tuning the background to 1-2 8-bit units;

5) image scaled down two times in a vain attempt to conceal misfocus :(

 

Done